They said it might never be done, but California physicist John Martinis claims to have taken the first big step toward ‘quantum supremacy.’
He and his colleagues have designed a computer that uses non-locality –what Albert Einstein disparagingly referred to as ‘spooky action at a distance’ – enabling it to accomplish in three minutes what would ordinarily take the world’s best supercomputer 200 centuries to complete.
Martinis, who both holds the Wooster Chair in experimental physics at the University of California, Santa Barbara, and a position with Google’s AI team, has long experimented with non-locality. He joined the Google team in 2014 specifically with the task of designing the first quantum computer.
One of the strangest aspects of quantum physics is non-locality, also poetically referred to as ‘quantum entanglement.’ The Danish physicist Niels Bohr discovered that once subatomic particles such as electrons or photons are in contact, they remain aware of and influenced by each other instantaneously over any distance forever, despite the absence of the usual things that physicists understand are responsible for influence, such as an exchange of force or energy.
When entangled, the actions – for instance, the magnetic orientation – of one will always influence the other in the same or the opposite direction, no matter how far they’re separated. Erwin Schrödinger, another one of the original architects of quantum theory, believed that the discovery of non-locality represented no less than quantum theory’s defining moment – its central property and premise.
To understand entangled particles, just imagine you’ve got a set of twins being separated at birth. One lives in Colorado, and the other in London.
Although they never meet again, both grow up to like the color blue. Both take a job in engineering. Both like to ski; in fact when one falls down and breaks his right leg at Vale, his twin breaks his right leg at precisely that moment, even though he is 4000 miles away, sipping a latte at Starbucks.
With quantum particles, once they are entangled, it’s like they retain a telepathic connection forever. Albert Einstein refused to accept non-locality; this type of instantaneous connection would require information travelling faster than the speed of light, he argued, which would violate his own special relativity theory.
Since the formulation of Einstein’s theory, the speed of light (about 983,571,058 feet per second) has been used as the absolute outer boundary on how quickly one thing can affect something else. Things are not supposed to be able to affect other things faster than the time it would take the first thing to travel to the second thing at the speed of light.
An ordinary ‘classical’ computer works by using its tiniest units of information, or ‘bits,’ valued at either 1 or 0. But in a so-called quantum computer, its bits – called ‘qubits’ for ‘quantum bits’ – can be valued at both 1 and 0 at the same time.
Presently, Martinis and his team at Google claim to have taken the first step toward computer non-locality, so that certain processes take a fraction of the time it takes to process information even with the fastest ordinary computer.
As they wrote in a recent paper published in Nature magazine, ‘Our Sycamore processor takes about 200 seconds to sample one instance of a quantum circuit a million times—our benchmarks currently indicate that the equivalent task for a state-of-the-art classical supercomputer would take approximately 10,000 years.’
Competitor IBM, which is also in the race to create the first quantum computer, has dismissed the idea that Google has reached ‘quantum supremacy’ (‘By its strictest definition,’ wrote an IBM team in a blog, ‘the goal has not been met.’)
However, this is not so far-fetched if you consider that quantum non-locality exists everywhere around us – including in the big sticks and stones world of the everyday.
Eleven years ago, biologist Graham Fleming, a biologist at the University of California at Berkeley, designed a study to understand exactly how plants are able to harness the power of the sun, convert it into energy and expel oxygen as a byproduct.
The miracle is not only the fact that the plant can manage this feat at all, but also that it does so with such ruthless efficiency, without losing so much as 5 per cent of the solar energy that comes its way.
The key to studying this extraordinary process involved tracking the path of electrons inside the protein scaffolding of the cell, which connect the plant’s exterior solar panels, or chlorosomes, the harvesters of sunlight, to reaction centers at the heart of the cells — the tiny crucible where the miracle of conversion takes place.
What Fleming discovered is nothing less than a giant chink in the entire edifice of accepted biology. Rather than a single pathway, the electrons reached their target so quickly by trying out several routes simultaneously.
Only when the final connection is made and the end of the road reached does the electron track its most efficient path retroactively and the energy follow that single path.
It is as if a person lost in a labyrinth had tried out all possible pathways all at the same time, and after finally discovering the correct pathway to the exit, eliminated all trace of his rehearsals.
Fleming’s discovery shows that the plant is so efficient because its messenger electrons are able to occupy more than one location at the same time.
A subatomic particle like those in Fleming’s plant essentially experiments with this pathway and then that pathway at the same time before choosing the optimum path to the reaction site.
Fleming made some of the first tentative forays into what has been called ‘quantum biology’ — producing the first evidence that life on earth is driven by the laws of quantum physics.
Once we accept that there are not two rules of the game – the science of the large and the science of the small – but a single quantum rule of all of life, we might finally produce that full-fledged quantum computer.